P2.G138: Early Heart Rate Patterns in Very Preterm Infants with and without Cystic Periventricular Leukomalacia

Background: Cystic periventricular leukomalacia (cPVL) occurs in about 5-10% of infants born very preterm (VPT < 32 weeks gestation). cPVL has been linked to fetal, perinatal and neonatal systemic inflammation which may be reflected by atypical heart rate (HR) patterns. We previously reported higher HR and lower HR variability in infants with severe intraventricular hemorrhage (IVH) (PMID 24556979;34450675) and abnormal HR variability in NICU patients later diagnosed with cerebral palsy (CP) (PMID 36174590; 37891365). In the current work, we tested the hypothesis that HR patterns shortly after birth differ in VPT infants with and without cPVL.

Methods: A single-center retrospective study was performed including all VPT infants admitted to a level IV NICU between 2012 and 2022 diagnosed with cPVL on brain ultrasound or MRI and with continuous HR data stored. Control infants with archived HR data and without cPVL, severe IVH or major congenital anomalies were matched 1:1 by gestational age (GA) and sex. Maternal and infant antenatal, perinatal and postnatal data were collected from the electronic medical record and from a NICU database (NeoData), including results of a General Movement Exam (GMA) if performed. HR data from bedside monitors was collected at 0.5 Hz (every 2s) using BedMaster technology. Hourly mean, standard deviation (SD), skewness, kurtosis and cross-correlation of HR and SpO2 (an indicator of apnea; PMID: 29141263) were calculated throughout the NICU stay. Clinical characteristics and HR data 24-48h after birth were compared between cPVL cases and matched controls using descriptive statistics for clinical variables and an unpaired t-test for HR analysis.

Results: 19 infants with cPVL and 19 matched controls were included (mean GA 27.1 +/- 0.3 weeks; 74% male). Inotrope-treated hypotension in the first week after birth occurred in 8/19 (42%) infants with cPVL and 5/19 (26%) controls. Postnatal steroids were administered to 6 infants with cPVL and 2 controls. GMA was performed in 6/19 infants with cPVL, was abnormal for all those tested, and 4/6 had cramped synchronized movements predicting high risk for CP. GMA was performed in 5/19 controls, 3 abnormal and none cramped synchronized (Table 1). Infants with cPVL had significantly lower HR from 24-48 hours after birth compared to controls (139 beats/minute +/- 3.15 versus 152 +/- 2.25, p< 0.0001)(Figure 1). There were no other significant differences in HR metrics in the first week after birth.

Conclusion: More infants in the cPVL group were male, had hypotension requiring inotropes, postnatal steroid exposure, and cramped synchronized movements on GMA. HR was significantly lower from 24 to 48 hours after birth for infants with cPVL compared to controls. Further work is needed to understand the physiology, associations, and clinical relevance of atypical HR patterns in NICU patients with cPVL.